Torque transferring assemblies are widely used in vehicles to transfer torque between the engine and the wheels. Typically, a torque transferring assembly is arranged between a transmission and an axle assembly, a power transfer unit and an axle assembly, or a transfer case and an axle assembly. To reduce weight, torque transferring assemblies typically include a tubular shaft spanning between a source of rotational energy and the axle assembly. Tubular shafts transmit and amplify vibration and noises from the engine, axle assembly, transmission, transfer case, and wheels. Yet another problem with tubular shafts in torque transferring assemblies is that they produce undesirable noise when rocks or other debris forcefully impact the tubular shaft during vehicle operation.
To address the production or transmission of noises by the torque transferring assembly, some manufacturers have used plugs or other internal dampers inserted at specific nodes within the tubular shaft to reduce specific frequencies of noise and vibration based on damping capability limitations. These plugs typically reduce only a narrow band of frequencies, are expensive and require increased assembly time to ensure correct installation at the specific node. Some internal dampers are heavy, thereby mitigating the weight saving benefits of the tubular shaft. Another problem with these plugs or internal dampers is that they generally are not capable of reducing impact noise.
Therefore, there is a need for a lightweight damper for hollow torque transferring assemblies that reduces noise and vibration issues over a wide frequency range to an acceptable level, and is cost efficient to produce and assemble.